Shuttle mechanism



Oct. 29, 19 A. F. CARLSON SHUTTLE MECHANISM Filed Nov. 26, 1937 2 Sheets-Sheet 1 INVENhJ ML. (MW,

A. F. CARLSON SHUTTLE MECHANISM Oct. 29, 1940. Y

2 Sheeis-Sheet 2 Filed Nov. 26, 1937 Patented Oct. 29, 1940 SHUTTLE MECHANISM Axel Folke Carlson, Stockholm, Sweden, asslgnor W to The Reece Button Hole Machine Company,

Boston, Mass, a. corporation of Maine Application November 26, 1937, Serial No. 176,414

6 Claims.

This invention relates to the thread-handling devices of lock-stitch sewing machines, and more particularly to a novel shuttle mechanism thereof.

It is among the objects of the present invention to provide a novel drive for a rotary shuttle which permits the unobstructed passage of a nontwisted thread loop around the shuttle.

It is another object of the present invention to provide novel structure which prevents the escape of the bobbin from its support on the shuttle as well as rotation of the bobbin together with the shuttle, without interfering with the passage of a non-twisted thread loop around the shuttle and bobbin.

The foregoing and other objects of the present invention, together with means whereby the latter may be carried into effect, will best be understood from the following description of an illustrative embodiment thereof ,shown in the accompanying drawings. The particular mechanism described and shown is, however, being chosen for purposes of exemplification merely, as it will be obvious to those skilled in the art that the invention, as defined by the claims hereunto appended, may be otherwise embodied without departure from the spirit and scope thereof.

In said drawings:

Fig. 1 is a front elevation, partly in section, of a shuttle mechanism which embodies the present invention. Fig. 2 is a section through the shuttle mechanism, taken substantially on the line 2-2 of Fig. 1.

Fig. 3 is a section taken substantially on the line 33 of Fig. 1. v Fig. 4 is a perspective view of the shuttle.

Fig. 5 is a perspective view of the bobbin case which is supported by the shuttle.

Fig. 6 is a perspective view of a detail of the present shuttle mechanism.

Fig. 7 is a perspective view of certain co operating elements-of the shuttle mechanism.

Fig. 8 is another perspective view of certain cooperating elements of the shuttle mechanism.

Figs. 9 and 10 are front elevations of the cooperating elements illustrated in Fig. '7, showing said elements in different positions of cooperation, however.

Fig. 11 is a sectional view of a modified shuttle mechanism.

Referring to the drawings and more particularly to Figs. -1, 2 and 3, the reference numeral 20 designates the horn of any conventional lockstitch sewing machine (not shown). Mounted on the horn 20 by means of screws 2| is a shuttle support 22, provided with a central opening 23 which is counter-bored at 24 .to form the race for a shuttle 25. A ring member 26 is mounted on the shuttle support 22 by means of bolts 21 and is adapted to retain the shuttle 25 in its race. The shuttle 25, which is substantially dish-shaped in cross section and approximates segmental shape in front elevation, as can be observed in Fig. 4 is provided with a peripheral rim 28 which rests in the race 24 (Fig. 3). The shuttle is also provided with diametrically opposite slots 29 which are adapted to receive the projecting driving ends 30 of a lever 3'I, pivoted at 32 centrally between its ends to a shaft 33 which has one end journalled in a bearing 34, formed integral with or mounted in any suitable manner on the horn 20 of the sewing machine. Shaft 33 may be driven in any suitable manner (not shown) in timed relation with the needle reciprocation. Inasmuch as the illustrated shuttle requires the greater part of one revolution for the passage of a thread loop therearound, the shuttle is so driven that it will make two revolutions to each needle reciprocation so that the take-up device (not shown) may perform its operation and the needle may go through its necessary motions for casting a new loop I during the intervening time period between successive passages of loops around the shuttle. More particularly, the entire lever 3| is straddled by a bifurcated transversehead 35 of the shaft 33 which prevents any appreciable bending of said lever 3| and, hence, not only maintains the driving ends 30 thereof in perfect alignment with 3 their respective slots 29 in the shuttle but also renders the pivot 32 free from any bending stresses so that said pivot is subjected only to shearing stresses when transmitting the driving force from the shaft 3'3 tothe lever 3|. Inasmuch as the ends 30 of the lever 3| are adapted alternately to drivingly engage the shuttle 25 and torotate the same continuously and at uniform vspeed, it is of the greatest importance that said driving ends 30 are in perfect alignment with their respective slots 29 of the shuttle while intermittently out of engagement therewith, and that they fit rather accurately into said slots 29 to avoid any lost motion between the shuttle 25 and the driving lever 3|. The other end of the shaft 33 may in any suitable manner he rotatably mounted in the sewing machine and held axially immovable so that an annular shoulder 36 of said shaft is in permanent engagement -with the-machined face 31 of the bearing 34.

The ends 90 of the lever 3| are in permanent cooperation with an annular cam 39 which is mounted in any suitable manner on the bearing 34 concentrically to the shaft 35. The active surface 39 of the cam 38 is a plane surface which extends at the inclination shown in Fig. 3 with respect to the axis of the shaft 33. More particularly, the inclination of the cam surface 39 is such that at least one of the depending ends 50 of the lever 3| projects into its respective slot 29 in the shuttle irrespective of the angular position of said lever, and that said ends 30 alternately move into and out of driving engagement with their respective slots 29. The continuous drive of the shuttle is assured inasmuch as either end 30 of the lever 3! remains in driving engagement with the shuttle until the other end has moved into driving engagement therewith. The angular disposition of the cam 38 is such that each end 30 of the lever 3| is in driving engagement with its respective slot 29 in the shuttle substantially during rotation through the angular distance A (Fig. 1), and is out of driving engagement with its respective slot 29 during rotation through the remaining angular distance. Hence, after the hook 40 of the rotating shuttle 25 has entered the thread loop 1, previously cast into the path of rotation of said hook by the axially reciprocating needle 42 on slight recession from its lowermost position into the position shown in Fig. 3, the rear leg 43 of said loop may pass along the rear surface 'of said shuttle and across a presently disengaged slot 29 thereof before the corresponding end 30 of the lever 3i reenters said slot. By the time the take-up device (not shown) of the sewing machine becomes operative after the loop I has been substantially passed around the shuttle, the other end of the lever 3| has already been moved out of driving engagement with its respective slot 29 in the shuttle and permits the withdrawal of said rear leg 43 of the loop from the shuttle between the latter and said other end of the driving lever 32. Consequently, the present shuttle drive does not require a twist in the loop Z in order that the same may pass around the shuttle without interference from the shuttle drive.

Projecting from the shuttle 25 is an eccentric pin ifiwhich rotatably receives the hollow shank as of a bobbin case i? that holds the usual bobbin (not shown). The bobbin case d? is provided with three angulariy spaced, radially projecting lugs 48, i9 and 5d. The lugs 65 and 5d are substantially diametrically opposite each other and serve to hold a cover (not shown) which is preferably hinged. in a notch 55 of the lug 58 and provided with a suitable extension that snaps into a notch 52 of the other lug 5%.. The lugs 48 and 59 are also provided with surfaces 53 and 5e, respectively, which are inclined with respect to the aixs of the bobbin case as shown in Figs. 5, 7, 9 and 10. Adapted to cooperate with these inclined surfaces 53, 5d are two correspondingly inclined surfaces 55 and 56, respectively, of a member 5! (Figs. 1, 2 and 6) which is mounted from rotating together with the shuttle by the surfaces 55 and 55, respectively, of the member 51. Inasmuch as the bobbin case 41 is mounted on the eccentric pin 45 of the shuttle, the former is bodily moved during rotation of the shuttle 25. Due to the presence of the surfaces 55 and 55 of the member 51, the bodily motions of the bobbin case are alternate rocking motions in opposite directions about the surfaces 53 and 54, respectively, of the bobbin case. Therefore, movement of the bobbin case 41, as caused by the eccentric pin 45, results in alternate engagement/and disgagement between the surfaces 53, 55 and 54, 55, respectively, of the bobbin case and the member 51, respectively, as can be readily understood. Consequently, gaps 58 and 59 alternately open and close between the surfaces 53, 55 and 55, 55, respectively, of the bobbin case 41 and member 51 (see Figs. 9 and In the angular position of the shuttle illustrated in Fig. 9, the eccentric pin 45 assumes an angular position in which it holds the bobbin case 41 at the end of one of its counter-clockwise rocking motions about the engaged surfaces 53, 55 of the bobbin case 41 and member 51, respectively, as a floating fulcrum, with the result that the gap 58 is entirely closed and the gap 59 is of maximum width. While the gap 59 is substantially open, the front leg 62 of the thread loop l'is gradually deflected through said open gap 59 by a skirt 5B which is integral with the shuttle 25 and has a thread-deflecting edge 6| (Figs. 4, 7 and 8) that gradually spreads said loop so. that said forward leg 62 passes through the gap 59 and to the front of the covered end 59 (Fig. 7) of the bobbin case M. Upon continued rotation of the shuttle 25 from the position shown in Fig. 9 to that shown in Fig. 10, the eccentric pin 45 first causes a rocking motion of the bobbin case 41 in clockwise direction as viewed in Fig. 9 and about the engaged surfaces 53, 55 of the bobbin case 41 and member 5!,respectively, as a floating fulcrum until the gap 59 is completely closed. Thereafter, the eccentric pin 5 again rocks the bobbin case counter-clockwise as viewed in Fig. 10 about the then engaged surfaces 54, of the bobbin case and member 51, respectively, as a floating fulcrum, with the result that the gap 58 gradually opens until it reaches its maximum width when the shuttle 25 arrives substantially at the position shown in Fig. 10. At this time, the loop 1 has passed sufiiciently far around the shuttle to permit any conventional take-up device (not shown) to start withdrawal of the loop lfrom the shuttle, whereupon the forward leg c2 of said loop passes through the open gap 56. Upon continued clockwise rotation of the shuttle from the position shown in Fig. 10, the open gap 58 is first gradually closed again, and the bobbin case 51 is thereafter rocked counterclockwise about the then engaged surfaces 53, 55 of the bobbin case 41 and member 51, respectively, as a floating fulcrum, with the result that the gap 59 gradually reopens to provide for the passage of the forward leg 52 of a new loop I therethrough substantially when the shuttle reaches again the position shown in Fig. 9. Inasmuch as the present shuttle makes two revolutions to each reciprocation of the needle, it is obvious that a thread loop is passed around the shuttle on alternate revolutions only of the latter. However, the gaps 58 and 59 open and close during each revolution of the shuttle to provide passage for the forward leg 62 of a loop. It is, therefore, obvious that the present bobbin case t! and cooperating member 51 can be used together with a shuttle that makes only one revolution to each needle to the plane of the inclined, active surface 39 reciprocation and, consequently, passes a thread loop around the bobbin on each revolution. It

can alsobe understood from the foregoing description that at least one of the inclined surfaces 53, 54 of the bobbin case is in engagement with its respective surface 55, 56 of the member tween the eccentric pin 45 of the rotating shuttle and the'hollow shank 46 of the bobbin case drags the latter about said pin 45 in the direction of rotation of the shuttle so that one of the surfaces 53, 54 of said bobbin case is urged into engagement with its respective surface 55, 56 of the stationary member 51, depending on the angular disposition of the eccentric pin 45 and, consequently, of the shuttle 25. Moreover, the mass of the lugs 49 and 50 of the bobbin case is considerably greater than that of the lug 48, and it willbe noticed particularly in Fig. '7 that the greater mass of the lugs 49 and 59 is disposed at one side of a vertical plane through the center axis of the bobbin case. This greater mass has a clockwise movement of rotation about the axis of the bobbin case which forces the latter into engagement with the member 51. Thus, the frictional resistance between the eccentric pin 45 and the bobbin case 41 and the explained movement of rotation of the lugs 49 and 50 combine frictionally to retain said bobbin case on its sup,- porting pin.45, regardless of whether the shuttle rotates or is at rest. The bobbin case 41 is furthermore positively retained on the eccentric pin 45 of the shuttle by a lug of the member 51 (Fig. 6) in conjunction with the inclined surfaces 55 and 6 of said member 51. It can be observed in Fig. 1, that slight counter-clockwise rotation of the bobbin case41 away from the surfaces 55, '56 of the member 51, for instance on manual removal of the bobbin from said case 41, immediately brings the bobbin case into a position in which said lug 10 is in the path of axial removal of the former from its supporting pin 45. Thus, the member 51 performs two-separate functions, to wit, preventing rotation of the bobbin case 41 together with the shuttle, and preventing axial escape of said bobbin case from its supporting pin 45 on the shuttle. -In addition, the explained alternate engagementbetween the two pairs of cooperating, inclined surfaces of the bobbin case 41 and the member 51 results in alternate opening and closing of the gaps 58 and 59, thus permitting the passage therethrough of the forward leg 62 of a non-twisted loop 1 without interference from said member 51.

Fig. 11 discloses a modified shuttle mechanism wherein the shuttle a is identical with, and supported in the same manner as, the shuttle 25 in Figs. 2 and 3. The shuttle-driving arm SM is, however, directly mounted on a shaft 1|, journalled in the illustrated inclined fashion in a bearing bracket 340, which is in turn suitably mounted on the horn of a lock-stitch sewing machine. In order that the driving fingers a of the arm 3Ia move alternately into driving engagement with the shuttle 25a, and in order that at least one of said driving fingers is in engagement with said shuttle irrespective of the angular position of the latter, the shaft 1| extends in the present instance substantially at right angles cam 38 in Fig. 3, is eliminated of the annular cam 38 in Fig. 3. Obviously, any

' heat-generating sliding friction between the driving lever 3m and an operating cam, such as in this modified shuttle mechanism. I claim: 7

1. In a shuttle mechanism, the combination of a rotatably mounted shuttle; a bobbin-case member provided with at least two angularly spaced shoulders; a non-rotatable member having at least two angularly spaced projections; and means carried by the shuttle for supporting said bobbin-case member for rotation about an axis parallel to the shuttle axis and for causing such relative movement between said members during rotation of the shuttle that said projections and shoulders alternately engage each other, said projections being in the path of rotation of said shoulders in the normal direction of rotation of the shuttle.

2 In a shuttle mechanism, the combination of a rotatably mounted shuttle; a bobbin case member provided with at least two angularly spaced shoulders; another non-rotatable member having at least two angularly spaced shoulders; and means carried by the shuttle for supporting said bobbin case member for rotation about an axis parallel to the shuttle axis and for causing such relative movement between said members during rotation of the shuttle that the shoulders of said members alternately engage each other, the shoulders of said other member being in the path of rotation of the shoulders. of said bobbin case member in the normal direction of rotation of the shuttle, and the shoulders of at least one of said members being so inclined with respect to the shuttle axis as to resist axial removal of said bobbin case member from said supporting means upon engagement with either shoulder of the other member.

3. In a shuttle mechanism, the combination of a rotatably mounted shuttle having a projecting eccentric pin parallel to the shuttle axis; a bobbin case' provided with at least two angularly spaced shoulders, said bobbin case being rotatably sup orted on said eccentric pin; and at least two stationary and angularly spaced surfaces in the path of, rotation of said shoulders'in the normal direction of rotation of the shuttle, said eccentric pin rocking the bobbin case during rotation of the shuttle such that said surfaces and shoulders alternately engage each other.

4. In a shuttle mechanism, the combination of a rotatably mounted shuttle; a bobbin-case member provided with at least two angularly spaced shoulders; a non-rotatable member having at least two angularly spaced projections; means carried by the shuttle for supporting said bobbincase member for rotation about an axis parallel to the shuttle axis and for causing such relative movement between said members during rotation of the shuttle that said projections and shoulders alternately engage each other, said projections being in the path of rotation of said shoulders in the normal direction of rotation of the shuttle and each engaged projection normally resisting the axial removal of said bobbin-case member from said supporting means; and means also carried by the shuttle for directing the thread of a loop passing around the rotating shuttle through the gap between each disengaged projection' and shoulder.

5. In a shuttle mechanism, the combination of a rotatably mounted shuttle; a bobbin case member; means supporting said member for ro tation in said shuttle about an axis parallel to the shuttle axis; and a stationary member, said: members having spaced pairs of abutments of which any engaged pair positively prevents rotation of the bobbin case with the shuttle in one direction, and said means causing such relative movement between said members during shuttle rotation in said one direction that said abutment pairs are alternately engaged.

6. In a shuttle mechanism, the combination 0! a rotatably mounted shuttle; a bobbin case member; means supporting said member for rotation in said shuttle about an axis parallel to the shuttle axis and for axial movement out of the shuttle; and a stationary member, said members having spaced pairs 01 abutments of which any engaged pair positively prevents rotation of the bobbin case with the shuttle in one direction and trictionally resists axial movement of. the bobbin case from the shuttle, and said means causing such relative movement between'said members during shuttle rotation in said one direction that said abutment pairs are alternately engaged.

am FOLKE CARLSON'. 

